CREATE TABLE tb(id int, [value] varchar(10))
INSERT tb SELECT 1, 'aa'
UNION ALL SELECT 1, 'bb'
UNION ALL SELECT 2, 'aaa'
UNION ALL SELECT 2, 'bbb'
UNION ALL SELECT 2, 'ccc'
--SELECT * FROM tb
/**//*
id value
----------- ----------
1 aa
1 bb
2 aaa
2 bbb
2 ccc
(5 row(s) affected)
*/
--2 在SQL2000只能用自定义函数实现
----2.1 创建合并函数fn_strSum，根据id合并value值
GO
CREATE FUNCTION dbo.fn_strSum(@id int)
RETURNS varchar(8000)
AS
BEGIN
DECLARE @values varchar(8000)
SET @values = ''
SELECT @values = @values + ',' + value FROM tb WHERE id=@id
RETURN STUFF(@values, 1, 1, '')
END
GO
-- 调用函数
SELECT id, VALUE = dbo.fn_strSum(id) FROM tb GROUP BY id
DROP FUNCTION dbo.fn_strSum
----2.2 创建合并函数fn_strSum2，根据id合并value值
GO
CREATE FUNCTION dbo.fn_strSum2(@id int)
RETURNS varchar(8000)
AS
BEGIN
DECLARE @values varchar(8000)
SELECT @values = isnull(@values + ',', '') + value FROM tb WHERE id=@id
RETURN @values
END
GO
-- 调用函数
SELECT id, VALUE = dbo.fn_strSum2(id) FROM tb GROUP BY id
DROP FUNCTION dbo.fn_strSum2
--3 在SQL2005/SQL2008中的新解法
----3.1 使用OUTER APPLY
SELECT *
FROM (SELECT DISTINCT id FROM tb) A OUTER APPLY(
SELECT [values]= STUFF(REPLACE(REPLACE(
(
SELECT value FROM tb N
WHERE id = A.id
FOR XML AUTO
), '<N value="', ','), '"/>', ''), 1, 1, '')
)N
----3.2 使用XML
SELECT id, [values]=STUFF((SELECT ','+[value] FROM tb t WHERE id=tb.id FOR XML PATH('')), 1, 1, '')
FROM tb
GROUP BY id
--4 删除测试表tb
drop table tb
/**//*
id values
----------- --------------------
1 aa,bb
2 aaa,bbb,ccc
(2 row(s) affected)
*/
查询数据库中所有的用户表和对应字段
查询语句查询所有用户表及其构：
SELECT TABLENAME=A.NAME,FIELDNAME=B.NAME,C.NAME,B.LENGTH FROM SYSOBJECTS A,SYSCOLUMNS B,SYSTYPES C WHERE A.ID=B.ID AND B.XTYPE=C.XTYPE AND A.TYPE='U' ORDER BY A.NAME
合并重复数据
SELECT TABLENAME, [values]=STUFF((SELECT ','+[FIELDNAME] FROM [XXXXXXXXXX] t WHERE TABLENAME=[XXXXXXXXXX].TABLENAME FOR XML PATH('')), 1, 1, '')
into ALLTable
FROM XXXXXXXXXX
GROUP BY [TABLENAME]
左链接查询
/****** Script for SelectTopNRows command from SSMS ******/
SELECT TOP 1000 [宫格属性]
,[ALLTable].TABLENAME
,[表名]
,[中文意思]
,[描述/关联实体]
,[IS指令]
,[最后修改时间]
,[最后执行人]
,[含有字段]
,[ALLTable].[values]
FROM [CeShiSQL].[dbo].[SQl表$] left join [CeShiSQL].[dbo].[ALLTable]
on [CeShiSQL].[dbo].[ALLTable].TABLENAME=[CeShiSQL].[dbo].[SQl表$].表名